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1.
A [4+1] Cyclative Capture Approach to 3H‐Indole‐N‐oxides at Room Temperature by Rhodium(III)‐Catalyzed CH Activation
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Dr. Yaxi Yang Xuan Wang Dr. Yuanchao Li Dr. Bing Zhou 《Angewandte Chemie (International ed. in English)》2015,54(51):15400-15404
The rhodium(III)‐catalyzed [3+2] C? H cyclization of aniline derivatives and internal alkynes represents a useful contribution to straightforward synthesis of indoles. However, there is no report on the more challenging synthesis of pharmaceutically important N‐hydroxyindoles and 3H‐indole‐N‐oxides. Reported herein is the first rhodium(III)‐catalyzed [4+1] C? H oxidative cyclization of nitrones with diazo compounds to access 3H‐indole‐N‐oxides. More significantly, this reaction proceeds at room temperature and has been extended to the synthesis of N‐hydroxyindoles and N‐hydroxyindolines. 相似文献
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3.
Heating of 1′‐(N‐substituted carbamoyl)methylspiro[2H‐1‐benzopyran‐2,2′‐[2H]indoles] with potassium hydroxide in ethanol yields diastereomeric 5a,13‐methano‐6H‐1,3‐benzoxazepino[3,2‐a]indole‐12‐carbox‐amides. Reduction of the latter with sodium borohydride affords 1,2,3,9a‐tetrahydro‐2‐hydroxyaryl‐9H‐pyrrolo[ 1,2‐a] indole‐3 ‐carboxamides. 相似文献
4.
Ruthenium(II)‐Catalyzed C−H Activation of Imidamides and Divergent Couplings with Diazo Compounds: Substrate‐Controlled Synthesis of Indoles and 3H‐Indoles
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Yunyun Li Dr. Zisong Qi Dr. He Wang Xifa Yang Prof. Xingwei Li 《Angewandte Chemie (International ed. in English)》2016,55(39):11877-11881
Indoles are an important structural motif that is commonly found in biologically active molecules. In this work, conditions for divergent couplings between imidamides and acceptor–acceptor diazo compounds were developed that afforded NH indoles and 3H‐indoles under ruthenium catalysis. The coupling of α‐diazoketoesters afforded NH indoles by cleavage of the C(N2)?C(acyl) bond whereas α‐diazomalonates gave 3H‐indoles by C?N bond cleavage. This reaction constitutes the first intermolecular coupling of diazo substrates with arenes by ruthenium‐catalyzed C?H activation. 相似文献
5.
Jian Fang Evan M. Howard Matthias Brewer 《Angewandte Chemie (International ed. in English)》2020,59(31):12827-12831
Structurally complex diazo‐containing scaffolds are formed by conjugate addition to vinyl diazonium salts. The electrophile, a little studied α‐diazonium‐α,β‐unsaturated carbonyl compound, is formed at low temperature under mild conditions by treating β‐hydroxy‐α‐diazo carbonyls with Sc(OTf)3. Conjugate addition occurs selectively at the 3‐position of indole to give α‐diazo‐β‐indole carbonyls, and enoxy silanes react to give 2‐diazo‐1,4‐dicarbonyl products. These reactions result in the formation of tertiary and quaternary centers, and give products that would be otherwise difficult to form. Importantly, the diazo functional group is retained within the molecule for future manipulation. Treating an α‐diazo ester indole addition product with Rh2(OAc)4 caused a rearrangement to occur to give a 2‐(1H‐indol‐3‐yl)‐2‐enoate. In the case of diazo ketone compounds, this shift occurred spontaneously on prolonged exposure to the Lewis acidic reaction conditions. 相似文献
6.
Synthesis of 6‐Aminoindolo[2,1‐a]isoquinoline‐5‐carbonitriles by the Cu‐Catalyzed Reaction of 2‐(2‐Bromophenyl)‐1H‐indoles with CH2(CN)2
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Kazuhiro Kobayashi Kosuke Ezaki Daisuke Hanioka Ippei Nozawa 《Helvetica chimica acta》2015,98(2):179-183
A series of 6‐aminoindolo[2,1‐a]isoquinoline‐5‐carbonitriles 4 have been prepared by treatment of 2‐(2‐bromophenyl)‐1H‐indoles 1 , available from 1‐(2‐bromophenyl)ethanones or 1‐(2‐bromophenyl)propan‐1‐ones by using Fischer indole synthesis, with propanedinitrile in the presence of a catalytic amount of CuBr and an excess of K2CO3 in DMSO at 100°. 相似文献
7.
Facile Installation of 2‐Reverse Prenyl Functionality into Indoles by a Tandem N‐Alkylation–Aza‐Cope Rearrangement Reaction and Its Application in Synthesis
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Dr. Xiaobei Chen Huaqiang Fan Prof. Dr. Shilei Zhang Chenguang Yu Prof. Dr. Wei Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):716-723
An unprecedented tandem N‐alkylation–ionic aza‐Cope (or Claisen) rearrangement–hydrolysis reaction of readily available indolyl bromides with enamines is described. Due to the complicated nature of the two processes, an operationally simple N‐alkylation and subsequent microwave‐irradiated ionic aza‐Cope rearrangement–hydrolysis process has been uncovered. The tandem reaction serves as a powerful approach to the preparation of synthetically and biologically important, but challenging, 2‐reverse quaternary‐centered prenylated indoles with high efficiency. Notably, unusual nonaromatic 3‐methylene‐2,3‐dihydro‐1H‐indole architectures, instead of aromatic indoles, are produced. Furthermore, the aza‐Cope rearrangement reaction proceeds highly regioselectively to give the quaternary‐centered reverse prenyl functionality, which often produces a mixture of two regioisomers by reported methods. The synthetic value of the resulting nonaromatic 3‐methylene‐2,3‐dihydro‐1H‐indole architectures has been demonstrated as versatile building blocks in the efficient synthesis of structurally diverse 2‐reverse prenylated indoles, such as indolines, indole‐fused sultams and lactams, and the natural product bruceolline D. 相似文献
8.
Wenzhong Huang Lingli Nang Xiangguang Li Lin Yuan Yinhai Ma Deqiang Liang 《中国化学》2015,33(10):1167-1172
Under the catalysis of only 3 mol% of Br2 at room temperature, indoles reacted rapidly with isatins to form biologically important 3,3‐bis(indole‐3‐yl)indoline‐2‐(1H)‐ones with high efficiency and wide substrate scope. Moreover, we demonstrated that p‐toluenesulfonic acid (TsOH) could serve as a surrogate to catalyze this transformation. 相似文献
9.
The cycloaddition between N‐protected 3‐{1‐[(trimethylsilyl)oxy]ethenyl}‐1H‐indoles and substituted maleimides (= 1H‐pyrrole‐2,5‐diones) yielded substituted pyrrolo[3,4‐a]carbazole derivatives bearing an additional succinimide (= pyrrolidine‐2,5‐dione) moiety either at C(5a) or C(10b) depending on the type of the protection group at the indole N‐atom. Derivatives substituted at C(10b) were isolated when the protection group, Me3Si or Boc (tBuOCO), was eliminated during the reaction (Schemes 2 and 3), whereas a substitution at C(5a) was observed when an electron‐withdrawing group, Tos (4‐MeC6H4SO2) or pivaloyl (Me3CCO), was not eliminated (Scheme 1). Complex results were found in reactions between 1‐(trimethylsilyl)‐3‐{1‐[(trimethylsilyl)oxy]ethenyl}‐1H‐indole, in contrast to formerly reported results (Scheme 3). Some derivatives of 1H,5H‐[1,2,4]triazolo[1′,2 : 1,2]pyridazino[3,4‐b]indole‐1,3(2H)‐dione were obtained from reactions with 4‐phenyl‐3H‐1,2,4‐triazole‐3,5(4H)‐dione (Scheme 2). All structures were established by spectroscopic data, by calculations, and one representative structure was confirmed by an X‐ray crystallographic analysis (Fig.). Finally, the formation of the different structure types was discussed, and compared with similar reactions reported in the literature. 相似文献
10.
One‐pot regioselective benzylation of pyrroles and indoles using zirconium tetrachloride is discussed. This has been achieved by in‐situ generation of di(1H‐pyrrol‐1‐yl)zirconium(IV) chloride and di(1H‐indol‐1‐yl)zirconium(IV) chloride. It was observed that benzylation reactions of these complexes using n‐BuLi occurred at C‐2 position for pyrrole and C‐3 for indole. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
11.
Johnny Sltt Tomasz Janosik Niklas Wahlstrm Jan Bergman 《Journal of heterocyclic chemistry》2005,42(1):141-145
Various synthetic applications of 3‐(cyanoacetyl)indoles, as well as syntheses of some related indoles, have been investigated. Diethyl 2‐(1H‐indol‐3‐yl)‐2‐oxoethylphosphonate and a methyl derivative thereof have been prepared in one step from indole. Moreover, it was demonstrated that 3‐(cyanoacetyl)indoles are useful starting materials for the preparation of for example 3‐(1H‐indol‐3‐yl)‐3‐oxopropanamides, 3‐heteroarylindoles or 3‐heteroaroylindoles. 相似文献
12.
Pd‐Catalyzed Cyclocarbonylation of 2‐(2‐Bromoaryl)indoles with CO as a C1 Source: Selective Access to 6 H‐Isoindolo[2,1‐a]indol‐6‐ones and Indeno[1,2‐b]indol‐10(5 H)‐ones
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A highly efficient and regioselective synthetic route to 6 H‐isoindolo[2,1‐a]indol‐6‐ones and indeno[1,2‐b]indol‐10(5 H)‐ones through the Pd‐catalyzed cyclocarbonylation of 2‐(2‐bromoaryl)indoles under atmospheric CO pressure has been achieved. Notably, the regioselectivity of the reaction was exclusively dependent on the structural characteristics of the indole substrates. With N‐unsubstituted indoles as the starting materials, the reaction afforded 6H‐isoindolo[2,1‐a]indol‐6‐ones in good‐to‐excellent yields. On the other hand, with N‐substituted indoles as the substrates, the reaction gave indeno[1,2‐b]indol‐10(5 H)‐ones in a highly regioselective manner. 相似文献
13.
Yaxi Yang Xuan Wang Yuanchao Li Bing Zhou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(51):15620-15624
The rhodium(III)‐catalyzed [3+2] C H cyclization of aniline derivatives and internal alkynes represents a useful contribution to straightforward synthesis of indoles. However, there is no report on the more challenging synthesis of pharmaceutically important N‐hydroxyindoles and 3H‐indole‐N‐oxides. Reported herein is the first rhodium(III)‐catalyzed [4+1] C H oxidative cyclization of nitrones with diazo compounds to access 3H‐indole‐N‐oxides. More significantly, this reaction proceeds at room temperature and has been extended to the synthesis of N‐hydroxyindoles and N‐hydroxyindolines. 相似文献
14.
Silvio Aime Mauro Botta Giancarlo Cravotto Luca Frullano GiovanniB. Giovenzana Simonetta GeninattiCrich Giovanni Palmisano Massimo Sisti 《Helvetica chimica acta》2005,88(3):588-603
Four new ligands for lanthanide ions based on the H3do3a (=1,4,7,10‐tetraazacyclododecane‐1,4,7‐triacetic acid) structure and bearing one N‐sulfonylacetamide arm were synthesized, i.e., H4dota‐NHSO2R=10‐{2‐[(R)sulfonylamino]‐2‐oxoethyl}‐1,4,7,10‐tetraazacyclododecane‐1,4,7‐triacetic acids 1a – e . A 15N‐NMR study of the 15N‐labelled Eu3+ complex of one such ligands, 1d , showed that the coordination of the N‐sulfonylacetamide arm involves the carbonyl O‐atom rather than the N‐atom. The relaxometric properties of the corresponding Gd3+ complexes were investigated as a function of pH and temperature. These complexes have relaxivities in the range 4.5–5.3 mM ?1 s?1, at 20 MHz and 25°, and are characterized by a single H2O molecule in their inner coordination sphere. The mean residence lifetime of this molecule is relatively long (500–700 ns) compared to other anionic complexes. The slow rate of H2O exchange can be justified by the extensive delocalization of the negative charge on the N‐sulfonylacetamide arm. The long residence time of the coordinated H2O allowed the observation of the effect of the prototropic exchange on the relaxivity. The study of the interaction between the complex [Gd( 1e )]‐ and HSA revealed a weak affinity constant highlighting the importance of a localized negative charge on the complex to promote a strong interaction with the protein. 相似文献
15.
Afsaneh Feiz Ghazaleh Imani Shakibaei Zahra Yasaei Hamid Reza Khavasi Ayoob Bazgir 《Helvetica chimica acta》2011,94(9):1628-1637
A new four‐component synthesis of spiro[4H‐indeno[1,2‐b]pyridine‐4,3′‐[3H]indoles] and spiro[acenaphthylene‐1(2H),4′‐[4H‐indeno[1,2‐b]pyridines] by the reaction of indane‐1,3‐dione, 1,3‐dicarbonyl compounds, isatins (=1H‐indole‐2,3‐diones) or acenaphthylene‐1,2‐dione, and AcONH4 in refluxing toluene in the presence of a catalytic amount of pyridine is reported. 相似文献
16.
Sankar Prasad Dey Dilip Kumar Dey Asok Kumar Mallik Lutz Dahlenburg 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o321-o322
The title compound, 2‐hydroxyphenyl 5‐(pyrrol‐2‐yl)‐3H‐pyrrolizin‐6‐yl ketone, C18H14N2O2, was isolated from the base‐catalyzed 1:2 condensation of 2‐hydroxyacetophenone with pyrrole‐2‐carbaldehyde. The pyrrole N—H and hydroxybenzoyl O—H groups are hydrogen bonded to the benzoyl O atom. The allylic C=C double bond of the 3H‐pyrrolizine system is located between ring positions 1 and 2, the C atom at position 3 (adjacent to the N atom) being single bonded. 相似文献
17.
Jessica Orrego Hernandez Jaime Portilla Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(5):363-368
Cyclohexylamine reacts with 5‐chloro‐3‐methyl‐1‐(pyridin‐2‐yl)‐1H‐pyrazole‐4‐carbaldehyde to give 5‐cyclohexylamino‐3‐methyl‐1‐(pyridin‐2‐yl)‐1H‐pyrazole‐4‐carbaldehyde, C16H20N4O, (I), formed by nucleophilic substitution, but with 5‐chloro‐3‐methyl‐1‐phenyl‐1H‐pyrazole‐4‐carbaldehyde the product is (Z)‐4‐[(cyclohexylamino)methylidene]‐3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐one, C17H21N3O, (II), formed by condensation followed by hydrolysis. Compound (II) crystallizes with Z′ = 2, and in one of the two independent molecular types the cyclohexylamine unit is disordered over two sets of atomic sites having occupancies of 0.65 (3) and 0.35 (3). The vinylogous amide portion in each compound shows evidence of electronic polarization, such that in each the O atom carries a partial negative charge and the N atom of the cyclohexylamine portion carries a partial positive charge. The molecules of (I) contain an intramolecular N—H...N hydrogen bond, and they are linked by C—H...O hydrogen bonds to form sheets. Each of the two independent molecules of (II) contains an intramolecular N—H...O hydrogen bond and each molecular type forms a centrosymmetric dimer containing one R22(4) ring and two inversion‐related S(6) rings. 相似文献
18.
Lilianna Chciska Magdalena Maecka Katarzyna Aranowska Justyn Ochocki 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(1):o4-o6
Molecules of the title compound, C8H12NO3P, exist as zwitterions. The positive charge formally located on the N atom is spread over the pyridyl ring. A partial delocalization of negative charge within the O—P—O system is observed. The conformational features and hydrogen‐bonding network of the title compound are compared with the structure of (2‐pyridylmethyl)phosphonic acid. 相似文献
19.
1,3‐Dichloro‐tetra‐n‐butyl‐distannoxane was firstly used to catalyze the direct substitution of 9H‐xanthen‐9‐ol with indoles at room temperature to afford a class of 3‐(9H‐xanthen‐9‐yl)‐1H‐indole derivatives in good to excellent isolating yield. Moreover, other nucleophiles (such as diketone and pyrrole) could also proceed smoothly in this methodology. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
20.
Can Liu Tao Miao Lei Zhang Prof. Pinhua Li Yicheng Zhang Prof. Lei Wang 《化学:亚洲杂志》2014,9(9):2584-2589
A novel and efficient palladium‐catalyzed C2 arylation of N‐substituted indoles with 1‐aryltriazenes for the synthesis of 2‐arylindoles was developed. In the presence of BF3 ? OEt2 and palladium(II) acetate (Pd(OAc)2), N‐substituted indoles reacted with 1‐aryltriazenes in N,N‐dimethylacetamide (DMAC) to afford the corresponding aryl–indole‐type products in good to excellent yields. 相似文献